Cassette threading arrangement in sewing machines

ABSTRACT

A sewing machine is disclosed in which the needle thread manipulating instrumentalities including a thread tensioning device, a check spring, and a thread take-up member may be threaded by the act of inserting into the machine a cassette including a supply of thread with provision for guiding and positioning the thread from the supply for introduction of the thread to the sewing machine thread manipulating instrumentalities when the cassette is inserted in the sewing machine.

United States Patent 1 Fritts 1 CASSETTE THREADING ARRANGEMENT 3,269,6718/1966 242/55.l9A

IN SEWING MACHINES [75] Inventor: Russell A. Fritts, Warren, NJ. PrimaryHampmn Hunter AttorneyMarshall J. Breen et al. [73] Ass1gnee: The SingerCompany, New York,

[57] ABSTRACT A sewing machine is disclosed in which the needle [22]Filed: Oct. 24, 1972 [21] PPL Q- 300,014 thread manipulatinginstrumentalities including a thread tensioning device, a check spring,and a thread 52 US. 112/218 R P member f be by 3 act of insertos 43/00mg mm the machine a cassette including a supply of 112/218 R, 221 threadwith provision for guiding and positioning the 137, 1371, thread fromthe supply for introduction of the thread [51] Int.

[58] Field of Search................

to the sewing machine thread manipulating instrumentalities when thecassette is inserted in the sewing ma chine.

[56] References Cited UNITED'STATES PATENTS 8 Claims, 12 Drawing Figures3,385,247 5/1968 Johnson et al. 112/218 R PAIENIED JUL3I ma liiliiillllllll 1 CASSETTE TIIREADING ARRANGEMENT IN SEWING MACHINES BACKGROUNDOF THE INVENTION It is difiicult to thread a conventional sewingmachine, not only because of the number of different thread guidesthrough which the thread must; be di. rected, but because the sequenceof threading of the various guides must be observed meticulously if thesewing machine is to, operate successfully.

Self-threading guides are known whereby an opera: tor may. introduce thethread laterally into the eyelets without releasing grasp. of the,thread but these self-v di suides 19 n t Q viate he p qb e ra y therequirement that each guide must be threaded suc-. cessively. andv inprecise. sequence.

The [L5, Pat. No. 3,385,247, May 28, 1968 of R. E. Johnson et al.discloses, anarrangement; for facilitating the threadsupply for asewingmachine needle by com-.

biningthe threadsupply and the stitch-forming instru- 2 mentality(needle) in one insertablepackage in the ma. chine, This patentedconstruction, however, can be used only with the mostv rudimentarystitch-fonning ar-. rangementand isnotadapted-for use with a sewingmachine which utilizes conventionalthread manipulating elements such. asa thread tensioning device, check spring and thread. takesup mechanism.

BRIEF SUMMARY OF THE INVENTION It is, anobjecpof; this invention toprovidean easy threading arrangement for a thread-carryingsewingmachine.stitchsforming,instrumentality, such as a needle, of the typewhich is adapted to cooperate with conventional types ofthreadmanipulating elements. The,

object ,ofthis invention is attained by the provision of a thread.cassette inwhieh-a supply of thread isstored and in, which, threadguides and nippers are, provided fonpositioning the thread suchthat uponinsertion .of the cassetteinto the sewingmachine, the sewingmachinethread manipulating elements will automatically be threaded properly.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings of a preferredembodiment of this invention:

F IG. 1 is a perspective view of a sewing machine having a threadcassette of this invention inserted therein,

FIG. 2 is an enlarged perspective view of the cassette with the cassettelidopened showing the path of the thread in p the cassette,

FIG. 3 is an enlarged elevational view of the cassette withthe lidremovedand including fragments of the sewing machine frame inverticalcross-section showing the cassette completely seated in the sewingmachine FIG. 6 isian enlarged perspective view of the sewing machinethread tension and check spring devices and including a fragment of thecassettewhich operates the; retractable thread guide associated with thecheck spring, Y I

FIG. 7 is an enlarged and elevational view of the sewing machine withportions broken away to illustrate the provisions for directing threadfrom the cassette to the sewing machine thread take-up arm,

FIG. 8 is a perspective view of the thread directing fin on the sewingmachine for directing thread from the cassette to the thread take-uparm,

FIG. 9 is a disassembled perspective view of those parts on that portionof the cassette which presents a span of thread to the thread directingfin of FIG. 8,

FIG. 10 is a cross-sectional view taken substantially along line 10-10of FIG. 7 showing that fragment of the cassette which is illustrated inFIG. 9 but including the thread as it is nipped before the cassette isfully seated in the sewing machine,

FIG. 11 is a cross-sectional view similar to FIG. 10 but showing thethread nipper released as when the cassette is fully seated in thesewing machine, and

FIG. 12 is a perspective view of the thread cassette of this inventionwith the cover closed.

Referring to FIGS. 1, 5 and 7, this invention finds utility in a sewingmachine indicated generally at 11 having a frame including a bracket arm12 and a work supporting bed 13. As shown in FIG. 7, the sewing machineincludes as one of the stitch-forming instrumentalities a needle 14secured to a needle bar 15 joumaled for endwise reciprocation in abearing sleeve 16 in the bracket arm 12. The needle bar is impartedendwise reciprocatory movement by a drive link 17 which embraces a crankpin 18 rotated by a sewing machine main shaft 19 in the bracket arm 12.The crank pin 18 also drives a take-up lever 20 which is pivoted as at21 to an anchor link 22 journaled on a fulcrum pin 23 in the bracketarm. The free extremity of the take-up lever is formed with a threadaccommodating take-up eyelet 24 from which eyelet extends a threadintroduction slot 25 having its mouth 26 located at a considerabledistance from the free extremity of the take-up lever 20.

The take-up constitutes one of a series of thread manipulating elementswhich are required to operate upon the thread which is directed to theneedle in a conventional lockstitch sewing machine. As shown in FIGS. 3to 6, the sewing machine bracket arm also carries a thread tensioningdevice, indicated generally at 30, which includes opposed threadengaging disks 31 arranged on a stud 33. The disks 3] may be biasedtogether by any known arrangement and serve frictionally to resistpassage of a thread therebetween.

Also effective to manipulate the thread adjacent to the tensioningdevice is a check spring 34 shiftable angularly about the stud 33 of thetensioning device. Also shiftably supported for turning movement aboutthe stud 33of the tensioning device is a plate 36 formed with a threadguiding finger 37 for engaging and guidingthe thread between the tensiondisks 31 and the check spring 34. The plate 36 also includes bifurcatedtangs 38 by which the plate may be turned to shift the thread guidingfinger 37 selectively between effective and retracted positions as willbe described hereinbelow.

The thread tensioning device 30, the check spring 34 and the threadtake-up eyelet 24 thus represent three different thread manipulatingelements to which a nee- 'dle" thread of a lockstitch sewing machinemust be di rected in sequence in order for lockstitches to be formedproperly. In accordance with this invention,

these thread manipulating elements may be threaded simultaneoulsy by theact of insertion into the sewing machine frame of a thread cassetteindicated generally at 40.

FIG. 5 illustrates a fragment of the sewing machine bracket arm andindicates the manner in which a cassette accommodating space 41 isdefined therein. A sheet metal plate 42 secured to the bracket arm 12defines the inside wall of the cassette accommodating space and anescutcheon panel 43 exteriorly on the bracket arm defines the outsidewall thereof. At each side, the sheet metal plate 42 is formed without-turned channel elements 44 and 45 which not only define oppositeends of the cassette accommodating space 41 but which provide tracksslidably to accommodate the cassette 40 for translatory movement intothe cassette accommodating space 41.

As shown in FIGS. 4 and 5, the tensioning device 30, check spring 34,and thread guiding finger 37 for the check spring are positionedcompletely within the cassette accommodating space 41, while the take-uplever only partly projects into the cassette accommodating space. Themouth 26 of the thread introduction slot leading to the take-up eyelet24, as shown in FIG. 7, is arranged completely beyond the cassetteaccommodating space 41 at the opposite side of the sheet metal plate 42.

Three separate techniques are used to direct the thread to thetensioning device and check spring 34, to the thread guiding finger 37,and to the take-up eyelet 24 respectively. As will be described ingreater detail hereinbelow, these three techniques involve: l) a directinsertion of the thread from the cassette into the thread manipulatingelement as in the case of the tensioning device and check spring; (2) ashift of the guide or element to be threaded from a retracted positionto an operative position in engagement with the thread as in the case ofthe thread guide 37; and (3) an arrangement for deflecting the threadout of the cassette accommodating space and into cooperative relationwith a remotely positioned element as in the case of the thread take-up.

For influencing insertion of a thread to the take-up eyelet, a U-shapedthread deflecting member or fin 50 is provided of which a detached viewis shown in FIG. 8. The deflecting member 50 includes a pair of spacedsubstantially parallel arms 51 and 52 joined by a web 53. The spacedarms 51 and 52 are formed with thread camming surfaces 54 and 55,respectively, which begin closely adjacent to the web at the top and areinclined downwardly away from the web 53. The thread camming surface 54terminates at the bottom in a large notch 56, while the thread cammingsurface 55 continues below that of the thread camming surface 54 andterminates in a rearwardly projecting lip 57 beneath which the arm 52 isformed with a notch 58 extending closely adjacent to the web 53. Belowthe notches 56 and 58, the arms 51 and 52 straddle and are secured to asupport block 59 into which is threaded a fastening screw 60 by whichthe thread deflecting member 50 is secured to the sheet metal plate 42.Preferably, the thread deflecting member 50 is secured to the sheetmetal plate 42 with the web 53 and the upper portion of the threadcamming surfaces 54 and 55 disposed within the cassette accommodatingspace 41. The spaced arms 51 and 52 of the thread deflecting memberextend opposite a vertical slot 61 in the sheet metal plate 42 and thelip 57 on the thread camming surface 55 extends through the verticalslot 61 to a position within the sewing machine bracket arm rearwardlybeyond the cassette accommodating space 4'15 as shown clearly in FIG. 7.

The sheet metal plate 42 carries a stop pin 65 and the web 53 of thethread deflecting member 50 on the sheet metal plate 42 also carries astop pin 66, which stop pins together define the seated position for thecassette 40 in the cassette accommodating space 41.

The sheet metal plate 42 additionally, is formed with an inturned finger67 to which is secured as by welding a resilient tab 68 formed with anangularly bent free extremity 69 to serve as a thread nipper release aswill be described hereinbelow. For a fine adjustment of the position ofthe resilient tab 68, a stop screw 70 threaded into the support block 59of the thread deflecting member is provided.

Referring particularly to FIGS. 2, 3, 4 and 12, the construction of thethread cassette 40 will now be described. The cassette includes a casing71 formed with straight and parallel side edges 72 and 73 which areshaped for cooperation with the channel elements 44 and 45 of the sheetmetal plate 42 on the sewing machine bracket arm and serve to guide thecassette in its movements into and out of the cassette accommodatingspace 41 in the sewing machine. The casing 71 is formed with a cavity 74for accommodation of a supply of thread such as the thread spool 75. Forthis purpose a spool pin 76 with thread spool frictioning means such asa spring 77 may be attached to the cassette casing 71. A lid 78 havinghinge elements 79 and 80 attached to the cassette casing closes thethread accommodating cavity 74 and may be opened selectively forinspection or refill if the thread supply. An aperture 81 may beprovided in the lid so that the remaining supply of thread within thecassette may be readily viewed.

The casing 71 'of the cassette is provided with a plurality of threadguides to which thread from the thread spool 75 must be directed insequence in order to ready the cassette for use with the sewing machine.A first thread guide 85 is secured by a fastening screw 86 in a positionin axial spaced relationship to the thread spool 75. A second threadguide 87 secured by a fastening screw 88 at one side of a recess 89formed in the casing 71 of the cassette. A third thread guide 96? whichis arranged at the opposite side of the recess 89 in the casing 71 and afourth thread guide 91 which is arranged at one side of a second recess92 in the casing 71 may be formed integrally and fastened by screws 93to a bracket 94 secured by screws 95' to the casing. The thread guides85, 87, 90 and 91 may be similarly con structed and provided each with athread introduction slot 96 so that the thread may be entered laterallytherein in a manner referred to as self-threading" in the sewing machineart.

A fifth thread guide indicated generally at 97 is arranged at theopposite side of the second recess 92 in the cassette casing and ispreferably of a different construction than the other thread guides. Thefifth thread guide which is illustrated in disassembled perspective inFIG. 9 and is illustrated in cross-section in FIGS. 10 and 11, includesa U"-shaped body member 98 formed with spaced substanially parallel arms99 and 100 extending upwardly from a web portion 101 at the bottom. Athread supporting blade 102 is arranged between the arms 99 and 100 ofthe body member 98 so that a sinuous path of thread will be defined byarms 99 and 100 and the thread supporting blade 102. The arms 99 and 100are preferably each formed with a downturned thread retaining finger103, which fingers serve to discourage inadvertent escape of a threadonce introduced into the sinuous path under the arms 99 and 100 and overthe blade 102. Against the outside of the arm 99 of the U-shaped bodymember 98 is arranged a thread nipping blade 104 formed with adownwardly extending nipper releasing arm 105. A thread nipper leafspring 106 is positioned alongside the thread nipping blade 104. Theleaf spring 106, thread nipping blade 104, the thread supporting blade102, and the U- shaped body member 98 may all be secured to the threadcassette casing 71 by a fastening screw 107. The thread supporting blade102 is preferably formed with an elongate aperture 108 for the fasteningscrew 107 to permit limited adjustment of the vertical position of theblade 102 to provide nicety of control of the thread passing through thefifth thread guide 97.

Projecting vertically beneath the U-shaped body member '98 is a wirethread guide 109 through which the thread is directed as it passes fromthe cassette.

As shown in FIG. 2, the casing 71 of the cassette lid 78 may be formedwith shallow channels 110 to provide for passageways through which thethread may extend between the successive thread guides of the cassette.The lid 78, moreover, is formed with a recess 111 complemental to therecess 89 in the casing.

Adjacent the recess 89, the casing 71 of the thread cassette carries abracket 120 which includes a finger 121 adapted, as will be describedhereinbelow, to cooperate with the bifurcated tangs 38 on the plate 36carrying the thread guide finger 37 to shift the thread guiding fingerfrom retracted to operative position upon insertion of the cassette intothe sewing machine.

The bracket 120 is also formed with a forwardlyinclined check springengaging blade 122 effective as shown in FIG. 6 during insertion of thecassette into the sewing machine to engage and depress the check spring34. Such depression of the check spring insures a favorable lead ofthread between the check spring and the thread tensioning disks 31 sothat the thread will find its way beneath the thread guiding finger 37.When the cassette is completely seated in the sewing machine as shown inFIG. 3, the blade 122 will have slipped past the check spring 34allowingthe check spring freedom for operative movement. A beveled upper edge123 of the blade 122 provides for passage of the blade upwardly past thecheckspring without interference when the cassette is removed.

The cassette casing 71 has pivoted thereon as at 129 a thread nippinglever 130 which includes a thread contacting finger l3l at one extremityof the lever for contact with thefirst threadguide 85 to resist movementof thread therethrough. A leaf spring 132 carried in the cassette casing71 biases thethread contacting finger into effective threadnippingposition against a thread guide 85. The thread nipping lever 130 alsoincludes a release arm l33'which is influenced by the channel element45of the sheet metal plate 42 during the last motion of insertion of thecassette into the sewing machine to shift the thread nipping leveragainst the force of the leaf spring 32 and to hold the nipper into openposition as shown in FIG. 3.

The thread nipping lever 130 engages the thread at one side of thethread manipulating instrumentalities to which the thread is to beintroduced. The thread nipping blade ltld engages and restricts passageof the thread at the opposite side of the thread manipulatinginstrumentalities to be threaded. Preferably, the thread nipping blade10d exerts a greater frictional resistance to movement of the threadthan does the nipper lever 130 so that if the influence of both nippersis exceeded, additional thread will be drawn from the thread supply andnot from the free end of thread which might unthread one or more of thecassette thread guides. When the cassette is moved into final positionwithin the eassette accommodating space 411 the nipper release arm 105of the thread nipping blade 1104i will contact the free extremity 69 ofthe tab 68 thus shifting the thread nipping blade MM into an openposition as shown in FIG. 11.

In operation, a cassette 40 when provided with a supply of thread andthreaded as shown in MG. 2 is ready for insertion into the sewingmachine after the lid of the cassette is closed. insertion of thecassette into the thread accommodating space All of the sewing machinesimultaneously introduces thread to the thread manipulatinginstrumentalities by the three different techniques described above. Forthreading the tensioning device 30 and the check spring 3d, the span ofthread between the second and third thread guides 87 and 9% of thecassette will be introduced directly thereto. The thread guiding finger37 will be shifted into retracted position shown in FIG. s when thecassette had been previously removed from the machine. During the finalmovement of the cassette into position the finger 121 on the cassettewill shift the plate 36 and pull the thread guiding finger toward andinto engagement with the thread which extends from the tensioning deviceto the check spring so that the relationship of parts as shown in FIG. 3will result.

The thread take-up eyelet 24 will be threaded when the cassette isinserted into the sewing machine by the action of the thread deflectingmember hilt which will engage the thread which spans the second recess92 between the thread guides and 911. The thread camming surface 54 and55 will shift this span of thread rearwardly through the slot 61 in theplate 42 into the sewing machine bracket arm and as the downwardmovement of the cassette proceeds, this deflected limb of thread will becarried over the lip E7 of the thread camming surface 55. As shown inFIG. 7, the take-up lever 20 at the bottom of its stroke will bepositioned such that the thread introduction slot 25 and particularlythe mouth 26 of the slot will be arranged directly beneath the lip 57 ofthe thread deflecting member. When the cassette is shifted completelyinto the cassette accommodating space in the sewing machine, therefore,the thread will be introduced to the slot 25 and thence to the eyelet 2dof the take-up lever. it is a requirement for successful operation ofthe easy threading arrangement of this invention that the main shaft 19of the machine be turned prior to insertion and withdrawal of thecassette into a predetermined position in which the take-up lever 2%will occupy substantially the lowest position of its path of motion asshown in FIG. 7. A set of cooperating indicia Mil, MB on the sewingmachine bracket arm i2 and on a handwheel 142 on the main shaft 19serves as reference for the setting of this predetermined machineposition for insertion and removal of the cassette.

Since the two spans of thread in the cassette extending one betweenthread guides 87 and 90 and the other between thread guides 91 and 95will be held taut by the operation of thread nippers 104 and 131 whilethe cassette is in any position other than a position completely seatedin the cassette accommodating space 41 in the sewing machine, these twospans of thread will be directed to the thread manipulatinginstrumentalities upon insertion of the cassette into the sewingmachine, and these spans of thread will be withdrawn from theinstrumentalities when the cassette is lifted out of the sewing machineframe. A recess 150 may be formed in the top surface of the sewingmachine bracket arm 12 providing a better grip for the operator indepressing and removing the cassette from the sewing machine.

When the cassette has been inserted into the sewing machine and thethread manipulating instrumentalities simultaneously threaded thereby,the wire guide 109, and consequently, the free end of the thread whichextends through the wire thread guide, will protrude beneath the levelof the escutcheon plate 43 as shown in FIG. 7, so that the operator mayeasily grasp this thread and draw it downwardly to thread the needle 14thus completing preparation for sewing.

The cassette threading arrangement of this invention is particularlyadvantageous where numerous changes of thread are necessitated in theoperation of the sewing machine, as where color changes may be requiredfrequently, or the like. With a number of cassettes 40 available eachprovided with a different type or color of thread, the machine may bereadied for sewing with a different color or type of needle threadsimply by removing one cassette, replacing another in its place, andrethreading the needle with the fresh thread. With another cassette inplace in the sewing machine the path of the thread from the thread spoolin the cassette to the needle becomes a free path when the threadnippers 131 and 104 are released. Any use of the thread which ispossible with conventional thread arrangements for sewing machine maythus be availed of with the present cassette, for instance, bobbinreplenishment while the bobbin remains in place in the loop taken iscompatible with the present cassette arrangement and any known type ofsewing operation such as darning, embroidery, or the like is equallycompatible therewith.

With a number of cassettes available each provided with a differentcolor or type of thread, storage of thread is no longer fraught with theproblem of thread snarling since the nippers 102, 131 will be effectiveto prevent accidental unwinding of the thread spools while the cassettesare stored.

Having set forth the nature of this invention, what is claimed hereinis:

l. A thread cassette for supplying thread to a sewing machine having atleast one thread manipulating element, said thread cassette comprising acasing formed with guide means dictating insertion of said threadcassette into a sewing machine only in predetermined orientation of saidthread cassette, support means on said casing for a supply of thread,thread guides on said casing adapted to accommodate in seriatim a threadleading from a supply of thread on said support means, and includingsuccessive thread guides arranged to position therebetween a span ofthread for introduction to the sewing machine thread manipulatingelement when the thread cassette is inserted into the sewing machine inthe predetermined orientation dictated by said guide means, andreleasable thread nipping means effective on a thread on each side ofsaid successive thread guides during insertion of said thread cassetteinto a sewing machine.

2. A thread cassette comprising a casing, support means on said casingfor a supply of thread, a series of thread guides on said casing adaptedto accommodate in seriatim the thread leading from a supply of thread onsaid support means and defining at least one span of said thread betweensuccessive ones of said thread guides, releasable thread nipping meanseffective on said thread at each side of said at least one span of saidthread, and orientation means on said casing effective to constrain saidthread cassette to move in a direction substantially perpendicular tosaid at least one span of said thread.

3. An easy threading arrangement for a sewing machine having a frame, athread carrying stitch-forming instrumentality, and at least one threadmanipulating element associated with said stitch-forming instrumentalityin said frame, said sewing machine frame being formed with a receptiontrack means defining a space for accommodation of a thread supplycassette, means on said sewing machine casing and projecting into saidcassette accommodating space for directing a span of thread to saidthread manipulating element, a thread supply cassette including acasing, support means for a thread supply in said casing, a series ofthread guides in said casing for accommodating in seriatim a thread fromthread supply on said support means and including a pair of successivethread guides arranged to define therebetween a span of thread fordelivery to said thread directing means upon insertion of said cassettealong said reception track means.

4. An easy threading arrangement for a sewing machine as set forth inclaim 3 in which a thread nipping means is provided on said threadsupply cassette effective to clamp a thread passing through said threadguides relatively to said cassette casing on opposite sides of said pairof successive thread guides defining said span of thread, andinterengaging releasing means for said thread nipping means carried onsaid sewing machine frame and on said cassette casing effective whensaid cassette is positioned completely within said accommodation spaceon said sewing machine frame.

5. An easy threading arrangement for a sewing machine as set forth inclaim 4 in which said thread nipping means includes separate threadnippers effective on a thread on opposite sides of said pair ofsuccessive thread guides, and in which that one of said thread nipperswhich is effective on the thread between said thread supply and saidpair of thread guides is materially less effective than the other one ofsaid thread nippers.

6. An easy threading arrangement for a sewing machine as set forth inclaim 3 in which associated with said stitch-forming instrumentality area plurality of thread manipulating elements including a movable threadtake-up member and a thread tensioning device, and in which said threadsupply cassette includes in said series of thread guides a pair ofsuccessive thread guides corresponding to each of said plurality ofthread manipulating elements, each pair of thread guides arranged todefine therebetween a span of thread for delivery to thread directingmeans associated with a respective one of said plurality of threadmanipulating elements.

7. An easy threading arrangement for a sewing machine as set forth inclaim 6 in which a check spring is arranged between said threadtensioning device and.

said thread take-up element on said sewing machine frame, a shiftablethread guide is carried on said sewing machine frame for movement from aretracted position out of the path of a thread from the threadtensioning device to said check spring to an effective position in thepath of a thread from the thread tensioning device to the check spring,and in which an operating member 8. An easy threading arrangement for asewing machine as set forth in claim 3 in which said thread manipulatingelement comprises a thread take-up arm formed with a thread eyelet andincluding a thread introducing slot leading from the thread eyelet to anopening exteriorly on the thread take-up arm, and in which said meansfor directing a span of thread to said thread manipulating elementcomprises a thread deflecting fin carried on said sewing machine frameand having one extremity projecting into said thread cassetteaccommodation space to deflect a span of thread defined on said cassettealong a camming surface formed on said thread deflecting fin, saidcamming surface on said thread deflecting fin extending intojuxtaposition with the exterior opening of the thread introducing slotin said thread take-up arm in one predetermined position of said sewingmachine stitch-forming instrumentalities.

t t t t! fl

1. A thread cassette for supplying thread to a sewing machine having atleast one thread manipulating element, said thread cassette comprising acasing formed with guide means dictating insertion of said threadcassette into a sewing machine only in predetermined orientation of saidthread cassette, support means on said casing for a supply of thread,thread guides on said casing adapted to accommodate in seriatim a threadleading from a supply of thread on said support means, and includingsuccessive thread guides arranged to position therebetween a span ofthread for introduction to the sewing machine thread manipulatingelement when the thread cassette is inserted into the sewing machine inthe predetermined orientation dictated by said guide means, andreleasable thread nipping means effective on a thread on each side ofsaid successive thread guides during insertion of said thread cassetteinto a sewing machine.
 2. A thread cassette comprising a casing, supportmeans on said casing for a supply of thread, a series of thread guideson said casing adapted to accommodate in seriatim the thread leadingfrom a supply of thread on said support means and defining at least onespan of said thread between successive ones of said thread guides,releasable thread nipping means effective on said thread at each side ofsaid at least one span of said thread, and orientation means on saidcasing effective to constrain said thread cassette to move in adirection substantially perpendicular to said at least one span of saidthread.
 3. An easy threading arrangement for a sewing machine having aframe, a thread carrying stitch-forming instrumentality, and at leastone thread manipulating element associated with said stitch-forminginstrumentality in said frame, said sewing machine frame being formedwith a reception track means defining a space for accommodation of athread supply cassette, means on said sewing machine casing andprojecting into said cassette accommodating space for directing a spanof thread to said thread manipulating element, a thread supply cassetteincluding a casing, support means for a thread supply in said casing, aseries of thread guides in said casing for accommodating in seriatim athread from thread supply on said support means and including a pair ofsuccessive thread guides arranged to define therebetween a span ofthread for delivery to said thread directing means upon insertion ofsaid cassette along said reception track means.
 4. An easy threadingarrangement for a sewing machine as set forth in claim 3 in which athread nipping means is provided on said thread supply cassetteeffective to clamp a thread passing through said thread guidesrelatively to said cassette casing on opposite sides of said pair ofsuccessive thread guides defining said span of thread, and interengagingreleasing means for said thread nipping means carried on said sewingmachine frame and on said cassette casing effective when said cassetteis positioned completely within said accommodation space on said sewingmachine frame.
 5. An easy threading arrangement for a sewing machine asset forth in claim 4 in which said thread nipping means includesseparate thread nippers effective on a thread on opposite sides of saidpair of successive thread guides, and in which that one of said threadnippers which is effective on the thread between said thread supply andsaid pair of thread guides is materially less effective than the otherone of said thread nippers.
 6. An easy threading arrangement for asewing machine as set forth in claim 3 in which associated with saidstitch-forming instrumentality are a plurality of thread manipulatingelements including a movable thread take-up member and a threadtensioning device, and in which said thread supply casseTte includes insaid series of thread guides a pair of successive thread guidescorresponding to each of said plurality of thread manipulating elements,each pair of thread guides arranged to define therebetween a span ofthread for delivery to thread directing means associated with arespective one of said plurality of thread manipulating elements.
 7. Aneasy threading arrangement for a sewing machine as set forth in claim 6in which a check spring is arranged between said thread tensioningdevice and said thread take-up element on said sewing machine frame, ashiftable thread guide is carried on said sewing machine frame formovement from a retracted position out of the path of a thread from thethread tensioning device to said check spring to an effective positionin the path of a thread from the thread tensioning device to the checkspring, and in which an operating member for said shiftable thread guideis carried by said thread supply cassette and is operative to shift saidthread guide into effective position when the thread supply cassette ispositioned completely within said accommodation space on said sewingmachine frame and is operative to shift said thread guide into retractedposition when said thread supply cassette is removed from saidaccommodation space.
 8. An easy threading arrangement for a sewingmachine as set forth in claim 3 in which said thread manipulatingelement comprises a thread take-up arm formed with a thread eyelet andincluding a thread introducing slot leading from the thread eyelet to anopening exteriorly on the thread take-up arm, and in which said meansfor directing a span of thread to said thread manipulating elementcomprises a thread deflecting fin carried on said sewing machine frameand having one extremity projecting into said thread cassetteaccommodation space to deflect a span of thread defined on said cassettealong a camming surface formed on said thread deflecting fin, saidcamming surface on said thread deflecting fin extending intojuxtaposition with the exterior opening of the thread introducing slotin said thread take-up arm in one predetermined position of said sewingmachine stitch-forming instrumentalities.